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I \ , ATTACHMENT FIELD PROCEDURES Stantec Consulting Corporation STANDARD PROCEDURE FOR WELL ABANDONMENTS USING A HOLLOW-STEM AUGER DRILL RIG Prior to drilling, the boring location is marked with white paint or other discernible marking and cleared for underground utilities through Underground Service Alert(USA). Once predrilling efforts to identify subsurface structures are complete, pre-cleaned hollow stem augers (typically 8 to 10 inches in diameter) are advanced using a rotary drill rig for the purpose of destroying the well casing, seal, and filter pack. In situations where more than one well casing was installed in a single bore hole, the drilling augers will be centered on the deepest well casing. Upon completion of drilling, the borehole is filled with cement grout. In areas where the borehole penetrates asphalt or concrete, the borehole is capped with an equivalent thickness of asphalt or concrete patch to match finish grade. All soil cuttings are temporarily stored on-site in 55-gallon DOT approved drums pending laboratory analysis, waste profiling and proper disposal. A label is affixed to the drums indicating the contents of the drum, suspected contaminants, date of drilling, borehole number, and depth interval from which the contents were generated. Related Procedures: • Standard Procedure for Equipment Decontamination STANDARD PROCEDURE FOR WELL ABANDONMENTS USING PRESSURIZED CEMENT GROUT The well casing is filled with cement grout emplaced via tremmie pipe inserted to the bottom of the well casing. Once filled, a pressure of 40 PSI is applied; additional cement is added as necessary. The well will be considered successfully destroyed when a pressure of 40 PSI can be maintained for a minimum of 5 minutes with the grout within the well casing dropping less than one foot. The protective well vault is then removed and the annular space is filled with additional cement grout. In areas where the well penetrates asphalt or concrete, the borehole is capped with an equivalent thickness of asphalt or concrete patch to match finish grade. All soil cuttings are temporarily stored on-site in 55-gallon DOT approved drums pending laboratory analysis, waste profiling and proper disposal. A label is affixed to the drums indicating the contents of the drum, suspected contaminants, date of drilling, borehole number, and depth interval from which the contents were generated. Related Procedures: 0 Standard Procedure for Equipment Decontamination